When adding tasks to your services, you need to ensure that you have already created your tasks before hand and have assignees to it, if not, no tasks will appear

To check if you have already created tasks, you need to go to Settings → Task builder

If nothing exists, you can click on Create New

To get started go to Shopping cart → Services → Manage Service

Scroll down to Tasks and you should see it here:

Once you have an existing order, and you complete the job, the Property Website will be created and you will see the task there ready to be started